It is often desireable to load the bed of a trailer, which would be pulled behind a truck or car, at ground level and after the bed has been loaded it is then possible to raise the bed to a position within the trailer for transport. Such a trailer would be advantageous to a home owner moving such equipment as a refridgerator, washer, dryer or stove where it is difficult to raise such articles to the height of the trailer and position them on the load carrying bed. By having the bed drop to the ground level, this difficulty is avoided. Such a trailer is also useful for loading other equipment and could be adapted for snowmobiles, motorcycles and the like, and/or boats, for example.
Ground loading trailers have been proposed in the past as exemplified by U.S. Pat. No. 3,788,675, U.S. Pat. No. 2,478,795 and U.S. Pat. No. 2,953,266. Most of these patents generally utilize the pivot axis defined by the wheels of the trailer in combination with a pivot arrangement associated with the tongue of the trailer to drop the bed to the ground position. Because of the somewhat complicated relationship of these components, the bed often tips forward and subsequently moves to the back, or first is lowered at the back thereof such that the bed can be at several angles during the loading thereof. This presents problems with respect to the stability of the articles loaded on the trailer, as well as the changing characteristics of the trailer with respect to placement of the load. Furthermore, problems occur with these structures as the pivot access defined by the wheels of the trailer are offset relative to the trailer frame due to the suspension system which further changes the manner in which the bed is lower to the ground.
Although a ground loading trailer is desireable for many applications, it is often desireable to have a tilt load carrying bed to facilitate unloading of such material as gravel, sand or soil. Furthermore, such a tilt trailer would be desirable for launching boats.
According to the present invention, a universal trailer is possible which has improved characteristics with respect to the lowering of the load carrying bed.